Category Archives: Tools

New Release of Color Blindness Simulator

The online Color BLIndness Simulator is a quite popular tool as many people are looking for a way to simulate some form of color vision deficiency. Usually if you hear about this handicap it’s very strange to think about, what the other person which suffers from color blindness really sees.

The first version the Color BLIndness Simulator was up and running now for many years and it was time to give it a fresh look and feel and some powerful new functionality. This was possible with the great work of MaPePeR who was inspired by my tool and took it to a new level. He made it much faster and added some really cool features to it:

  • Drag and drop your image or use the old-fashioned upload button.
  • Zoom in and out with incredible speed.
  • Use a lens to see the difference between the normal image and the chosen simulation.

All those enhancements were put together by him into a library called jsColorblindSimulator. I would like to thank MaPePeR very much for this great work!

color-blindness-simulatorAs with the first version it is still possible to simulate all forms of color vision deficiency:

There is also a very colorful initial image available which can be converted into the different types of color vision deficiencies. This way you don’t even need to use your own images.

The new version also includes the better algorithm from HCIRN by Matthew Wickline. If this new version would not be working correctly on your browser (as it uses more modern technologies) the old first version is still available as Coblis1.

I very much hope you enjoy the new Color BLIndness Simulator and happy simulating ;-).

Color Blind Check released!!

Color Blind Check is available on Google Play Store: Android App – Color Blind Check.

Dear friends of Colblindor. Many you have been asking, when the official release of Color Blind Check will be available. It took a long time to develop and test it. But finally the release is ready for you!

With Color Blind Check you get a tool right in your hands which is easy to use and gives you instant feedback on your color vision abilities. Doesn’t matter what kind of color blindness you are suffering from, with this tool you’ll detect it and get detailed information about severity and type of your vision deficiency.

To promote this new kind of color blindness test you can access further informations on Or have a look at this introductional video to see it in action.

Color Blind Check is available on Google Play Store: Android App – Color Blind Check.

This new kind of check offers a broad set of features:

  • Testing color vision deficiency in two to four minutes.
  • Quick CBC for testing color blindness in 30 to 60 seconds.
  • Simple to handle, no special instructions needed.
  • Pause, restart whenever needed during testing.
  • Cancel/stop during running test.
  • Measuring type and severity of color vision deficiency.
  • Statistics of how many tests have been taken.
  • Direct link to most recent Color Blind Check result.
  • Direct link to highest Color Blind Check score.
  • Left-hand mode for easy testing.
  • Testing in portrait or landscape mode possible.

Let me know what you think about this new kind of color vision deficiency check through my contact page or by sending an email to If you like it rate it on Google Play Store and give me some thumbs up!

Color Blind Check is available on Google Play Store: Android App – Color Blind Check.

Color Blindness Simulation in Short Films

Carlos Hernandez Matas created in 2011 three short films demonstrating the three main forms of color blindness: Deuteranopia, Protanopia and Tritanopia. There are many simulators for color blindness available online. One of them can be found right here on Colblindor: Coblis — Color Blindness Simulator.

Carlos explaines how he did those videos:

This is a program that retrieves images from a live video feed or from a video file stored in a drive and performs in real-time a color transformation to show how the video would be seen by one of the three kinds of dichromat color blind people. In this video, it’s shown the transformation for people with tritanopia.




More information can be found on his website at

Subway Maps for Colorblind People

Paul Wynne, an occasional colorblind underground user of the London subway, says

What is a straightforward glimpse at a map for most travellers there, is a nightmare of trying to separate similar colours for me,…

This topic is not new to colorblind people. Also in 2007 a group of Norwegian Students thought about Improving the Readability of Public Transport Maps for Colorblind Travelers. Subway Maps in general are definitely not an easy thing to decipher for peoply with any form of color vision deficiency.

Because of that Paul decided to design a new kind of map, which enhances the color information of each subway line with an additional unique pattern. This way it should be possible for any type of colorblind person to read the map easily.

Colorblind London Subway Map

The combination of color and the idea of the scattered pattern supports the readability extremely. For me as a strongly red-blind person, it is much easier to spot the correct line and to find my way around the map. In opposite to most other pattern ideas, which highlight the pattern very prominently, this patterns are just a subtle support for the colors. And because of that, the pattern enhanced colored lines are not only easy to match but also don’t disturb the map as a whole.

In 2006 there was also the decision by Japan’s Public Facilities Making Life Easier for Colorblind People. When we look at Tokyo’s subway map now, we can also see some improvement in the readability.

Colorblind Tokyo Subway Map

In this case the designers went along a different path. They decided to use letters to identify the different lines uniquely. A combination of the line letter and the station number enhances the readability and makes it much easier to find your way around the map. This is definitely an improvement to the old version. But on the other side I personally think that the letters are also a little bit confusing and the map gets to crowded with all the information.

What do you think about the different subway maps for colorblind people from London and Tokyo? Do you think this could be a possibilty to enhance any kind of colored maps? Which color, pattern combination do you think is the most effective one for colorblind users?

You can find the London map of Paul including some further information at: A Map of the London Underground for Colourblind People.

Colorful – A Color Detection App

Colorful is an application for mobile devices that provides a fast, easy and handy way of recognizing colors. The application can assist a color blind person in detecting colors both in a live video feed from a mobile device’s camera, a photograph that was taken previously or saved from an email and even photos from various social networks (e.g. Facebook, Live).

Recognize and name colors with Colorful

Designed by 3 Computer Science students from the Hebrew University of Jerusalem, Colorful uses color interpretation and compensation algorithms and augmented reality technologies that may be integrated into almost every mobile smart phone device. Thanks to the intuitive user interface and straight-forward design, Colorful has won the WPAppItUp contest from Microsoft Corporation and was elected as the Editor’s choice.

Colorful boasts three major features that practically turn it into a one-stop shop:

  1. Recognize colors with 4 different naming levels, ranging from your basic colors (i.e. Red, Green, Blue, Yellow etc.) and up to a full dictionary of 16.5 Billion color values (Hexadecimal notation).
  2. Tag your favorite or most important colors with a name of your choosing! This comes in very handy when you are out shopping for clothes and want to find a shirt in that special color you look so good in. All you have to do is when you see a color you want to remember, tag it with a meaningful name and then next time you see it Colorful will let you know!
  3. Daltonize the colors on the screen according to your own type of color blindness (Protanopia, Deuteranopia, Tritanopia). You can use this filter on the live camera feed or with a photo. Never again pick up a bad batch of bananas!
Daltonized image (right) for color blind users

As a first step, the application was made publicly available on September 20th 2011 on the Windows Phone Marketplace and can be used on any Windows Phone 7 that runs the latest operating system (Mango, 7.5). Down the road, the developers inform that they intend on posting the application to more mobile platforms including Android, iOS (iPhone, iPod Touch, iPad) and the upcoming Windows 8 OS.

Windows Phone 7 users may get Colorful for FREE on the windows Marketplace and may choose to upgrade it for a small fee to gain additional functionality. Get it here (both Free and premium versions are available).

20 iPhone Apps for the Color Blind

Even if you are suffering from color blindness the iPhone can be used as your little helper tool. Different developers had a look into this niche and developed some nice Apps specially designed to help colorblind people or to educate the ones which don’t know how this looks and feels like.

Having a closer look into the different Apps designed around color vision deficiency I found 5 types or categories which can be used to describe them. Most helpers can be found in the group of ColorNaming. But there are also some interesting tools around CVD Simulation or even CVD Compensation/Daltonizing.

  • ColorNaming: Name a color from an image or the live picture while usually pointing to it. Some even speak the color or use some special algorithms to get the best fit. There is also a huge range in available color names.
  • CVDSimulation: Simulate the different types of color vision deficiency. This is similar to my online tool Coblis — Color Blindness Simulator.
  • CVDCompensation: In some form try to help colorblind people by adjusting certain colors so you can recognize them. Some even use some enhanced algorithms known as Daltonize.
  • MatchingColors: Find colors on a picture which match to the one you chose.
  • ColorHarmonies: Find harmonizing colors. This is certainly a perfect guide for all of us color blind, when we try to find an outfit that fits together!

I suppose HueVue: Colorblind Tools needs to be mentioned specially, as this is the only App which includes not only all of those five categories but it also the only one which tries to give some hints in color harmonies! And on top of that it’s even free to use. So if you have a look into those tools don’t miss that one.

Personally I don’t have an iPhone and didn’t test any of those Apps. So the descriptions are taken from the Apps pages and just altered to fit in. If you have any experience with one or even some of those Apps, please share your knowledge with us in the comments section.

HueVue: Colorblind Tools

HueVue: Colorblind Tools
by AppFoundry (Free App)

HueVue is a color tool for the iPhone that helps people with color vision deficiencies (commonly referred to as color blindness) to identify, match and coordinate colors. If you or someone you know has trouble with colors, or if you’re interested in a cool color identification, matching and coordination tool, then HueVue is for you!

Type: ColorNaming, CVDSimulation, ColorHarmonies, CVDCompensation, MatchingColors
ColorBlinds Easy

ColorBlinds Easy
by R2Pro BV

ColorBlinds Easy is the easy to use tool to help you as a colorblind person to distinguish colors and gain understanding and respect from family and friends for your color deficit by simulation. Daltonize is a method to improve contrast between red and green and with Simulate you can show your family and friends what your world looks like.

Type: CVDSimulation, CVDCompensation

Colorblind Helper

Colorblind Helper
by Zip Zest

Colorblind? Unsure or confused about the color of things. Quickly find out what colors others see and what they call them with Colorblind Helper. With its simple and easy to use interface there’s no more wondering whether you’re wearing a green tie with a red shirt, or a green tie with a green shirt.

Type: ColorNaming, MatchingColors

Chromatic Vision Simulator

Chromatic Vision Simulator
by Kazunori Asada (Free App)

The “Chromatic Vision Simulator” is a chromatic simulation tool. It makes a simulated video of each chromatic from the built-in camera and shows you how people with a specific type of color vision deficiency is seeing the world and this in real-time.

Type: CVDSimulation

Colorblind Vision

Colorblind Vision

Transform your iPhone into a real-time color blindness vision device! This app simulates the most severe color vision deficiencies. It’s all in real-time. Just launch the app and look at the world around you through your iPhone. You will experience how red and green colors all becomes yellow and brown.

Type: CVDSimulation

Chromatic Glass

Chromatic Glass
by Kazunori Asada (Free App)

“Chromatic Glass” divides the color spectrum into segments so that such colors do not overlap depending on the type of color deficiency a user suffers from. It adjusts lightness and chromaticity of color segments in real-time to further help users to identify colors.

Type: CVDCompensation

Color Blind Aid

Color Blind Aid

The Color Blind Aid iPhone app enables people with red-green color blindness to detect red and green in their environment and pass color blindness tests in real-time using augmented reality technology. Adjust sensitivity of red or green detection for indoor, outdoor, virbrant, dull, or test conditions.

Type: CVDCompensation


by ChewSoft

Colorblind is a game that challenges your ability to memorize and create colors. The premise of the game is simple; after being shown a color, and you must reproduce it. You have a series of ‘lifelines’ at your disposal that add to your strategy…but in the end…only you can determine whether or not you are truly ‘Colorblind’.

Type: Game


by Comparatel (Free App)

Kolorami analyses colours of a picture for the pleasure or to help partially sighted persons. Regular mode uses the camera to analyse the colors of what is in its visual field. The other mode ‘Screenshots ‘ allows you to reach photographs or screenshots stored in the library, to analyse colors.

Type: ColorNaming

Colorblind Assistant

iSpectrum Color Blind Assistant
by Wishbone Apps

Colorblind? You are not alone! Nearly one in twelve men, and one in one hundred women are colorblind. But you’re in luck: iSpectrum quickly and easily identifies any color by name! Simply touch your photo wherever you need to know the color and shake your device to reveal the RGB (Red/Green/Blue) components of any color.

Type: ColorNaming

ColorBlind Assistant

ColorBlind Assistant
by Brook Seaton

Use your iPhone or iPod Touch’s photo library to quickly identify colors. Quickly draw a circle around the test area. The app performs the following:
– identifies the hue, saturation and lightness
– percentage of the test area
– highlights the identified pixels

Type: ColorNaming

Color Reader

Color Reader
by IRLMobile Software (Free App)

Color Reader is an innovative concept allowing the user to “touch” camera live video to know the color of something. This is a fantastic way for people who are color blind to check colors. This app has been especially designed using the iPhone accessibilities feature.

Type: ColorNaming

Say Color

Say Color
by HotPaw Productions (Free App)

Speaks the name of the nearest color in the center of a camera preview pane using speech synthesis. If you lock the exposure and color balance while aiming at something medium neutral gray under your current scene’s lighting, the color naming scheme will be more accurately centered in the RGB gamut.

Type: ColorNaming


by Stephen Sullivan (Free App)

ColorIn detects colors with the iPhone camera. Simply point your camera and take a picture and ColorIn will tell you what the most dominant color is for that part of your image.


Colorblind Avenger

Colorblind Avenger
by Brian Wardle

The perfect tool for anyone who is colorblind. Now you’ll be able to identify the color of anything just by taking a picture of it with your iPhone! Touch anywhere on the image to see the color of that area. Displays color names and shades as well as rgb decimal and hex values. Designed to be quick and easy to use!

Type: ColorNaming

Color Curious

Color Curious
by Vais Salikhov

Ever looked at something and wandered what color it is? Want to know what name best describes the color you see – or the color you cannot see due to color blindness? Whether you are simply curious, or truly unable to perceive differences between certain colors, Color Curious is for you.

Type: ColorNaming


by Svep Design Center AB

ColorHelper is a small utility designed with the colorblind in mind, but its also of use for anyone interested in knowing the RGB color value for a specific spot in an image. Choose an existing photo or take a photo with the built-in camera, and select a spot where you would like to know the color value.

Type: ColorNaming

ColorBlind Suite

ColorBlind Suite
by Threeplicate

This application helps you find colors in real-time (augmented-reality) from your iPhone’s camera or photos in your library. There are two modes:
– Live Mode: Play with images directly coming from your iPhone’s camera
– Static Mode: Use images from your photo library or take a new photo

Type: ColorNaming


by sunset software Ltd Liab. Co

The ColorDetect iPhone app gives you the possibility to detect colors in real time using augmented reality technology. The name and the RGB values of the detected colors are displayed in real time on the user interface. ColorDetect detects the colors with a 5 point detection algorithm to improve the detection quality.

Type: ColorNaming


by Tilenus Consultores, S.L.

aidColors is an application that allows visually impaired to identify the color of things. Also can be a funny game for children. aidColors allows to perform an easy and fast color recognition by means of the iPhone camera.

Type: ColorNaming

ColorAdd: A Color Coding System

The designer Miguel Neiva developed a color coding system called ColorAdd which shall help colorblind people around the world. Simple and easy with many applications. Let’s have a closer look at it.

basic color codes
ColorAdd Basic Color Shapes

The system is based on three basic color shapes representing the primary colors blue, yellow, red and two forms for black and white. While mixing those basic graphics like you would mix colors themselves this results in a list of 21 basic colors including lighter (mixing in white) and darker (mixing in black) shades.

color palette color codes
21 Basic Color Codes of the ColorAdd System

This is it. Some more shapes for grey, silver and gold, but nothing else. That’s the whole ColorAdd system. At the first glance this is really simple and easy.

The designer claims that you don’t really have to memorize all those shapes as it works like mixing real colors. If you know the basic shapes you’re all set. In a way that’s true. But as I’m not that good on mixing colors—remember I am colorblind—I have to think about it twice if I’m right with my color mixture guess.

  • Simple: Yes. But somewhere you have to explain the system in my language as the symbols can’t easily be associated with the right colors.
  • Intuitively: No. Why don’t you use some sort of symbols which everybody associates with a certain color like fire, water and sun?
  • Nice design: Yes. Yes I like it. Simple shapes, they are nice to look at.
  • Robust usage: No. Hold some of them upside down and you will get the wrong color.

But the most important question to answer is: Can this color coding system be an added value for color blind people? This is what the designer claims and what it is actually all about. I don’t think so. Here are a few examples in my everyday life to support my point of view:

  1. The banana couldn’t change such a shape if it turns ripe. A big issue for me.
  2. Red/green led lights often already include some icon to show you something. So you can’t enhance them with another one and I’ll never know if it’s red or green.
  3. Ok, I would know if my shirt is blue or green. But I’m still not sure if it matches my purple tie or red trousers.
  4. And in most cases already now the manufacturers could add some sort of icon or pattern to help colorblind users in many situations. But they don’t do it and such a color code wouldn’t be easier to decipher than some simple icons.

Nice but unusable for me. I would be very glad if I get proven wrong in the future, if ColorAdd starts to get used and enhances my life in some way I can’t see yet.

Photoshop CS4 Accessibility Enhancement Incorporating Color Blindness

Photoshop CS4
Photoshop CS4

If you are designing graphics for a web page you have to keep in mind to make them also accessible to colorblind persons.

With Photoshop CS4 Adobe introduces soft proofing for color blindness, a great support just for this task.

The new soft proofing filters for color vision deficiency were developed in corporation with the Japanese Color Universal Design, a user-oriented design system, which has been developed in consideration of people with various types of color vision, to allow information to be accurately conveyed to as many individuals as possible.

Adobe Photoshop CS4 supports the following two color blindness filters, which combine the two most common forms of color vision deficiency:

Photoshop CS4 Color Blindness Option
Soft Proofing on Color Blindness

To determine whether your document is CUD-compliant or not, step through the following three simple steps:

  1. Convert the document to RGB color mode, which provides the most accurate soft proofs for color blindness.
  2. To simultaneously view the original document and a soft proof, choose Window > Arrange > New Window (optional).
  3. Choose View > Proof Setup > Color Blindness, and then choose either Protanopia-type or Deuteranopia-type.

To comply with CUD, you have to check your document in both views.

If you are a graphic/web designer, don’t forget to check your graphics on accessibility for colorblind users. Photoshop CS4 is one of the tool which can help you to fulfill this task—the color blindness simulator Coblis another (online) one. You might find some other helpful tools on my list of 15 Tools If You Are (Not) Colorblind.

Thanks to Jay Kinghorn and his article on Photoshop CS4: Color Blindness Proofing. You can also find more information on color blindness validation at the Adobe Photoshop CS4 accessibility overview.

Color Blindness: Can Colored Contacts Help You?

Many people who either newly learn about their color blindness or who would like to get a job which requires normal color vision, are looking for a way out. As there is no cure for color vision deficiency, improving color vision with lenses for the colorblind seems to be a nice possibility.

The question arises now, can such colored contacts really help you if you are colorblind?

Colored Glasses
Possible view through colored glasses.
Photo taken by Malingering

The following discussion refers to a product called ChromaGen, most probably the best known colored contacts aiming to help colorblind people.

The ChramaGen: A practitioner report is the most often cited report about visual aids for colorblind people. Unfortunately this source seems to be very optimistic and more like some surreptitious advertising.

It is well known, that colored contacts can only alter the perceived colors but can not enhance the spectrum. For example Dr. Natalie P. Hartenbaum states very clearly that lenses don’t correct color blindness contrary to some of the vendors, which make it look like as they could cure color blindness with their products.

ChromaGen lenses
Colored contact one eye only

Unfortunately I can not tell you anything about my personal impressions as I have never tried such lenses. But I would like to cite some others who did try colored contacts in hope to find something against their color vision deficiency under certain circumstances or even in everyday life.

Faborito says the following about his ChromaGen lenses (Link):

My life has changed in a way a have no words to describe. Last year i saw red for the first time in my life. Is amazing!!!! You have no idea what is like to see a coke can or a tomato in full brilliant red. It’s spectacular. I used them every day, and for photography are great.

Tabascokid is also sharing his story about the Chromagen lenses (Link):

[…] The thing that is not explained in the brochures is that despite you suddenly having a broader range of visible colours, depth perception and contrast, it doesn’t help in actually recognising the colours. When I attempted to edit skin tones and subtle casts, I was still just as much in the dark. The primary colour looked lovely and punchy but I never really had issues with these anyway. Tones and hues were as confusing as ever. My brain still couldn’t get the differences.

Chris made the following experiences (Link):

With ChromaGen only one tinted lens is worn, this provides colour contrast but I found it distracting as I was unable to coordinate the contrasting visual data. Although I passed the Ishihara Colour Test with this system, I was still unable to name colours. The ColorView system changed the colour spectrum but at the expense of darkening the visual spectrum overall. This system was more akin to wearing sunglasses than anything else as I still was unable to identify colours confidently and still failed the colour test.

Azmole tried the two systems ChromaGen and ColorView (Link)

I did have some improvement when testing them with the Ishihara test. The opthamologist with Colorview had me go outside in daylight to use the lenses and many reds that I normally could not see came into view. I did not purchase the lenses because I was more interested in passing a color vision test and felt even with the lenses I would fail.

Now judge yourself if you wont to give colored visual aids a try to improve your color vision. But you have to know, that not one product can cure color blindness but only alter your color perception.

Read more details about colored contacts and glasses at Improving Color Vision with Lenses for the Colorblind.

15 Tools If You Are (Not) Colorblind

The following list of on- and offline tools for colorblind persons was put together by JNvB, the founder and owner of

This is an overview of available software and websites which either help and assist you if you are suffering from color blindness (Visolve, Daltap, eyePilot™) or tools that can show you how the world looks like for colorblind persons. Next to that, programs are indicated that can recognize color and can show the name and/or code (e.g. RGB).

Assistive Software for Colorblind People

Visolve by Ryobi System Solutions

Visolve Deflector
Visolve Deflector

Using a filter, Visolve allows better discrimination of colors by making colors lighter and/or darker, or increasing the saturation.

Unique is the ability to give each color a different hatch pattern, which is very useful for charts or diagrams.

The filters of Visolve:

  • Red/Green filter: red colors lighter, green colors darker
  • Blue/Yellow filter: blue colors lighter, yellow colors darker
  • Saturation filter: increases the intensity of all colors
  • Filtering: colors other than the specified color are darkened
  • Hatching: each color is hatched differently


  • Windows NT, 2000 or XP (probably works on 98 and Me)
  • Mac OS v10.4 or higher (probably also v10.2 and up)

Download: Visolve
Free for personal and non-commercial use.

Daltap by Glenn Heylen

Daltap Flash Unit
Daltap Flash Unit

Daltap has several features combined of which the flashing feature is the most useful. By flashing, it shows where a picked color is on your screen. Next to that, it can give the name of the color at the tip of mouse and it can also zoom in the area that is near the mouse.

The features of Daltap:

  • Naming feature: show the name of the color (basic and detailed)
  • Flashing feature: chosen color flashes on the screen
  • Mini zoom feature: enlarges the area around the mouse


  • Windows XP, Vista with Windows .NET Framework 2.0

Download: Daltap
Free to use.

eyePilot™ by Tenebraex

eyePilot Gray Tool
eyePilot™ Gray Tool

Several filters that allows better identification of colors by graying out all colors except the one chosen or by flashing a picked color. It can also make a color turn black by clicking on the name and it can show the name of color. On top of that, it can change the hue of colors, increasing the contrast between colors.

The filters of eyePilot™:

  • Gray filter: all colors gray but the picked color
  • Flashing filter: a chosen color flashes
  • Name filter: shows the name of the color the mouse points at
  • Hue filter: adjusts the saturation of colors


  • Windows NT, 2000 and XP
  • Mac OS v10.2 and higher

Download: eyePilot™
Fully functional trail version for 30 days. Thereafter an activation code is needed for which you have to pay $34.00.

ColorBlindExt by Onkar Rukar, Gaurav Savkar, and Tushar Pagar


This Firefox add-on offers the possibility to change websites, text and figures such that it is better readable for the colorblind. This can be done while browsing or via a menu with the following filters:

  • Red filter (for protanopia and protanomaly)
  • Green filter (for deuteranopia and deuteranomaly)
  • Blue filter (for tritanopia and tritanomaly)
  • Monochromacy


  • FireFox 2.0 or higher with Java Runtime Environment 1.5 or Java Advanced Imaging Run Time 1.1.3 or higher.

Link: ColorBlindExt

Color Blindness Simulation

Color Oracle by Bernhard Jenny and Nathaniel Vaughn Kelso

Color Oracle Deuteranopia Settings
Color Oracle Deuteranopia Settings

Places a filter over the screen to simulate colorblindness directly showing how it looks like for a colorblind person.

Color Oracle can simulate the three main types of color blindness:

  • Deuteranopia (green-blindness: most common form of color vision deficiency)
  • Protanopia (red-blindness: rare form)
  • Tritanopia (blue-blindness: very rare form)


  • Windows 2000, XP or Vista with Java 6
  • Mac OS v10.4 or higher
  • Linux with Java 6

Download: Color Oracle
Free to use.

ColorDoctor by Fujitsu


ColorDoctor not only simulates website display, it is also possible to simulate real-time display of for example moving images such as Flash by selecting the “Transparent” mode. It is possible to show the display content through four different conversion filters:

  • Grayscale
  • Protanopia
  • Deuteranopia
  • Tritanopia

The simulation result can be stored in various file formats, including BMP, JPEG, PNG, TIFF, and GIF.


  • Windows XP and Vista with Windows .NET Framework 1.1 or higher

Download: ColorDoctor
Free to use.

Sim Daltonism by Michel Fortin

Sim Daltonism
Sim Daltonism

Sim Daltonism filters in real-time the area around the mouse pointer and displays the result—as seen by a color blind person—in a floating palette.

Sim Daltonism can simulate eight types of colorblindness:

  • Monochromacy (complete)
  • Monochromacy (partial)
  • Protanomaly (red-weakness)
  • Protanopia (red-blindness)
  • Deuteranomaly (green-weakness)
  • Deuteranopia (green-blindness)
  • Tritanomaly (blue-weakness)
  • Tritanopia (blue-blindness)


  • Mac OS X 10.2.8 or higher

Download: Sim Daltonism
Free to use.

Online Color Blindness Simulation

Coblis by Colblindor

Coblis - Color Blindness Simulator

Coblis – Color Blindness Simulator

Coblis was designed to help non colorblind people to understand how an image looks like if you have a certain type of color vision deficiency.

You can either try the different types of color blindness on the given sample picture or upload your own images and see how they look if you would be colorblind.

The following types of color blindness are supported by Coblis:

  • Normal Color Vision
  • Red-Blind/Protanopia
  • Green-Blind/Deuteranopia
  • Blue-Blind/Tritanopia
  • Red-Weak/Protanomaly
  • Green-Weak/Deuteranomaly
  • Blue-Weak/Tritanomaly
  • Monochromacy/Achromatopsia
  • Blue Cone Monochromacy

Link: Coblis

Vischeck by Bob Dougherty and Alex Wade

Vischeck Daltonize Tool

The online service of Vischeck offers two types of simulation:

  • Vischeck: shows how pictures look for colorblind people
  • Daltonize: corrects images if you are colorblind

Vischeck itself can simulate the three main types of color blindness either using an image or by running it directly on a webpage:

  • Protanopia
  • Deuteranopia
  • Tritanopia

Daltonize makes it possible to adjust the ratio of red/green & blue/yellow and brightness of colors of images making them more readable for a colorblind person.

Next to the website, Vischeck offers a plug-in to do the simulations offline with the help of Adobe Photoshop or ImageJ (see Vischeck downloads):

  • VischeckPS – Windows
  • VischeckPS – Mac
  • VischeckJ 1.0

Link: Vischeck

Colorblind Web Page Filter by Matthew Wickline

Colorblind Web Page Filter Settings

The purpose of colorblind webpage filter is, as the name already suggests, to show how webpages are seen by colorblind people.

To do this, you can choose between all different kinds of color vision deficiency:

  • Monochromacy
  • Blue Cone Monochromacy
  • Protanomaly (red-weakness)
  • Protanopia (red-blindness)
  • Deuteranomaly (green-weakness)
  • Deuteranopia (green-blindness)
  • Tritanomaly (blue-weakness)
  • Tritanopia (blue-blindness)

Additionaly it is possible to toggle stylesheet inclusion, image filtering and the special case of non-gif image filtering.

Link: Colorblind Web Page Filter

Color Vision by Cal Henderson

Color Vision
Color Vision

When designing a website, brochures, etc, Color Vision comes in very handy.

On the website you pick text and background color and check how this looks like in the case of:

Trichromat: Normal
Anomalous Trichromat:   Protanomaly Deuteranomaly Tritanomaly
Dichromat: Protanopia Deutanopia Tritanopia
Monochromat: Typical Atypical

Link: Color Vision

Color Recognition

Eyedropper by



Enlarges the area around the tip of the mouse and tells which color it points to in several different color systems like HEX, RGB, and CMYK.

Next to that, it is possible to make some image capturing or use the value switchable mode, which allows you to choose between normal, grayscale and websafe colors.


  • Windows 95, 98, NT, 2000, XP, and Vista

Download: Eyedropper
Free to use.

WhatColor by Hikaru Nakahara

WhatColor Features

Enlarges the area around the tip of the mouse one to four times and tells which color it points to in several different color systems like RGB, decimal, HSV and HLS.

Additionally it gives the name of the color the mouse points to, which is very handy for colorblind users. And on top of that it can even pronounce the color names.


  • Windows 95, 98, Me, NT, 2000, XP, and Vista

Download: WhatColor
Fully functional trail version. Thereafter an activation code is needed for which you have to pay $8.00.

Online Color Recognition

Color Name & Hue by Colblindor

Color Name & Hue

Color Name & Hue

By giving in a color as a RGB, HSB, or hexadecimale colorsystem value, Color Name & Hue associates a color name and the corresponding hue out of more than 1600 colors.

Color names can also be found by placing the circle on one of the main colors followed by moving around the slider to find the hue of the color of interest.

Link: Color Name & Hue

Name that Color by Chirag Mehta

Name that Color
Name that Color

You can either select a color by its name, enter a hexadecimal color value or select a color on a color selector wheel. Name that color will find the closest match out of a list of more than 1500 colors and name it.

Link: Name that Color

Thanks very much to JNvB from for this comprehensive list of tools for colorblind and not colorblind people. If you know of any more please add them in the comments section.